The pupil-teacher ratio has risen to an average of 18.3:1 in nursery, primary and secondary schools, the worst for 15 years. The average pupil-teacher ratio in primary schools in January was provisionally 22.9:1 and secondary schools provisionally 16.5:1. In England and Wales more than one million children are taught in classes of more than 30. Union leaders predict that action against class size could escalate in the autumn term.